Ion implantation is an important process in semiconductor/microelectronic manufacturing. The ion implantation process is used in integrated circuit fabrication to introduce dopant impurities into semiconductor wafers. The desired dopant impurities are introduced into semiconductor wafers to form doped regions at a desired depth. The dopant impurities are selected to bond with the semiconductor wafer material to create electrical carriers and thereby alter the electrical conductivity of the semiconductor wafer material. The concentration of dopant impurities introduced determines the electrical conductivity of the doped region. Many such impurity regions are necessarily created to form transistor structures, isolation structures and other electronic structures, which collectively function as a semiconductor device.
In an ion implantation process, a gas material is used that contains the desired dopant element. The gas is introduced into an ion source chamber, i.e., ionization chamber, and energy is introduced into the chamber to ionize the gas. The ionization creates ions that contain the dopant element. The ions are extracted from the ion source chamber in the form of an ion beam of desired energy. Extraction can be carried out by applying a high voltage across extraction electrodes. When high purity is desired, the beam is transported through mass analyzer/filter to select the species to be implanted. The ion beam can then be accelerated/decelerated and transported to the surface of a semiconductor wafer for implantation of the dopant element into the semiconductor wafer. The ions of the beam penetrate the surface of the semiconductor wafer to form a region of desired electrical conductivity.
A problem with the ion implantation process involves deposition of gas material residues on the surfaces of the ion source chamber and components contained within the ion source chamber. This can result in accumulated residue deposits that interfere with the successful operation of the ion source chamber, for example, electrical short circuits caused from residue deposits formed on low voltage insulators in the ion source chamber and energetic high voltage sparking caused from residue deposits formed on insulators in the ion source chamber. The residue deposits can adversely impact the normal operation of the ion implanter, cause frequent downtime and reduce tool utilization. Safety issues can also arise due to the emission of toxic or corrosive vapors when the ion source chamber and components contained within the ion source chamber are removed for cleaning. It is therefore necessary to remove the accumulated deposit formations from the surfaces of the ion source chamber and components contained within the ion source chamber to minimize any interference with the successful operation of the ion source chamber.
Therefore, a need exists for removing the accumulated deposit formations from the surfaces of the ion source chamber and components contained within the ion source chamber. It would be desirable in the art to develop cleaning methods for removing the accumulated deposit formations from the surfaces of the ion source chamber and components contained within the ion source chamber so as to minimize any interference with the successful operation of the ion source chamber.